odd behavior with git-rebase

Hey all-
	I hit a strange problem with git rebase and I can't quite decide if its
a design point of the rebase command, or if its happening in error.  When doing
upstream backports of various kernel components I occasionally run accross
commits that, for whatever reason, I don't want/need or can't backport.  When
that happens, I insert an empty commit in my history noting the upstream commit
hash and the reasoning behind why I skipped it (I use git commit -c <hash>
--allow-empty).  If I later rebase this branch, I note that all my empty commits
fail indicating the commit cannot be applied.  I can of course do another git
commit --allow-empty -c <hash>; git rebase --continue, and everything is fine,
but I'd rather it just take the empty commit in the rebase if possible.

I know that git cherry-pick allows for picking of empty commits, and it appears the rebase script uses cherry-picking significantly, so I'm not sure why this isn't working, or if its explicitly prevented from working for some reason.

anyone have any insight?

Thanks & Regards Neil